docs: def hash_monitor_names(service):
      """
      Uses the get_mon_map() function to get information about the monitor
      cluster.
      Hash the name of each monitor.  Return a sorted list of monitor hashes
      in an ascending order.
      :param service: six.string_types. The Ceph user name to run the command under
      :rtype : dict.   json dict of monitor name, ip address and rank
      example: {
          'name': 'ip-172-31-13-165',
          'rank': 0,
          'addr': '172.31.13.165:6789/0'}
      """
      try:
          hash_list = []
          monitor_list = get_mon_map(service=service)
          if monitor_list['monmap']['mons']:
              for mon in monitor_list['monmap']['mons']:
                  hash_list.append(
                      hashlib.sha224(mon['name'].encode('utf-8')).hexdigest())
              return sorted(hash_list)
          else:
              return None
      except (ValueError, CalledProcessError):
          raise